The present disclosure relates to a varnish impregnation apparatus and a varnish impregnation method, and in particular to a varnish impregnation apparatus and a varnish impregnation method that are suitable to impregnate a stator coil mounted to a stator core with varnish.
There have hitherto been known a varnish impregnation apparatus and a varnish impregnation method for impregnating a stator coil mounted to a stator core with varnish (see Japanese Patent Application Publication No. 2007-166712 and Japanese Patent Application Publication No. 2007-097238 for example). The varnish impregnation apparatus described in Japanese Patent Application Publication No. 2007-166712 includes a support that rotatably supports a stator in which a stator coil is mounted to a stator core. The support includes a workpiece rotary shaft inserted into a cavity portion provided at the axial center of the stator core. The workpiece rotary shaft is used to support the stator on the radially inner side of the stator, and to rotate the stator through rotation of the workpiece rotary shaft.
The varnish impregnation apparatus described above includes a dropping nozzle that drops varnish toward a coil end portion of the stator rotated while being supported by the support, and a heating device that heats the stator supported by the support. The heating device feeds hot air toward the stator supported by the support. The heating device preliminarily heats the stator in order to reduce the viscosity of the varnish to be dropped before the varnish is dropped onto the coil end portion of the stator, and heats the dropped varnish to cure the vanish after the varnish is dropped onto the coil end portion of the stator.
In the varnish impregnation apparatus described in Japanese Patent Application Publication No. 2007-097238, meanwhile, an induction heating coil is inserted into a cavity portion provided at the axial center of a stator core, a stator is heated through induction heating, and varnish impregnation is performed after the stator is transferred to another station for varnish impregnation.